1. Field of the Invention
The present invention relates to a method for allowing a substrate holding/rotating device that has a spin base to hold a substrate, and relates to a substrate processing apparatus that includes this substrate holding/rotating device and a substrate transfer mechanism. Examples of substrates to be processed include semiconductor wafers, glass substrates for liquid crystal display devices, glass substrates for plasma displays, substrates for photomasks, substrates for optical disks, substrates for magnetic disks, substrates for magnet-optical disks, substrates for FEDs (Field Emission Displays), ceramic substrates, and substrates for solar cells.
2. Description of Related Art
A substrate processing apparatus that processes substrates, such as semiconductor wafers, is roughly divided into a batch type processing apparatus that processes a plurality of substrates in one operation and a single substrate processing type apparatus that processes to-be-processed substrates in a processing chamber one by one at a time. In a generally-used single substrate processing type apparatus, a single substrate is horizontally held in a processing chamber, and is rotated or is supplied with a processing liquid in accordance with the contents of processing.
The single substrate processing type apparatus includes a spin chuck. A plurality of chuck pins are evenly spaced in a circumferential direction on the upper surface of a spin base of the spin chuck. Each chuck pin is disposed so as to be switchable between two kinds of operational states, i.e., between a closed state in which contact is made with the peripheral edge of a substrate and an open state in which contact is not made with the peripheral edge of a substrate. The substrate is held by the spin chuck by sandwiching the substrate between the chuck pins in a horizontal direction.
The substrate is held by the spin chuck as a result of a cooperative operation between the chuck pin and a horizontal support pin. One example of a substrate holding operation performed by the spin chuck is disclosed by Japanese Patent Application Publication No. 2014-45028. In Japanese Patent Application Publication No. 2014-45028, a spin chuck in a substrate processing apparatus is composed of a disk-shaped spin base, a plurality of holding bases spaced along a circumference corresponding to the outer peripheral shape of a substrate in the peripheral edge of the upper surface of the spin base, and a spin motor that rotates the spin base around a vertical rotational axis passing through the center of the spin base. The holding base includes a horizontal support pin that supports the substrate from below from its undersurface and chuck pins that sandwich the substrate therebetween from the direction of the side of the substrate.